The use of modular office furniture systems is currently very wide spread in modern office interior design. The advantages of using partitions in a modular office system include increased efficiency in the use of space and individual offices with permanent walls may be largely eliminated in open office designs. As a result, a tenant of leased commercial space may minimize the cost of leasehold improvements, and may occupy and vacate premises rapidly through assembly and disassembly of modular components.
Conventionally a partition comprises an interior hollow rectangular frame constructed of roll formed sheet metal channel sections welded together in a rigid assembly. Electrical wiring and communication cables are accommodated in the hollow interior of the partitions, and are passed between partitions through holes punched in the webs of frame members. Partitions are connected together at their vertical end frame members into various geometric office maze patterns and cladding panels are hung on the frames to enclose and conceal the supporting frames and wiring.
Commonly the vertical frame members have a series of longitudinally spaced slots within which dogs extending from the cladding panels are engaged. In a like manner shelves, desktop brackets, filing cabinets and other components of the modular office furniture system are hung on the partitions to complete the modular furniture assembly.
The fabrication of conventional partition frames often involves several operations which require special tooling and machine setups. For example, where frame members are constructed of formed sheet metal channels, openings for wiring, notches for connections to other frame members and slots for hanging accessories are punched in a flat sheet metal blank. The blank is then bent into a channel shape in a rollforming operation, or on a brake press. The formed channels are then fitted together in a jig and welded at rigid connections.
It will be apparent that where different sized frame members are used and where the configuration of members vary, numerous machine setup modifications must be made. Production may involve the preparation of a number of different frame member configurations each of which may require separate inventory, machine setups, production scheduling and drawings. Therefore it is desirable to simplify the design of frame members as much as possible to minimize production costs, inventory requirements, and provide maximum flexibility in manufacturing scheduling.
It is also desirable to minimize the use of welding as a means for connecting frame components. The heat from welding can distort metal frames, and a further manufacturing step may be required to straighten metal frames which have become twisted, or cambered through the welding process. In addition, welding thin sheet metal frames may require relatively highly skilled workers, and quality control supervision.
A welded metal frame is for all practical purposes, impossible to modify after fabrication. An improperly fabricated welded metal frame must be scrapped and very little of the material can be salvaged for reuse. If a purchaser of a partition system wishes to modify the furniture layout, whole partitions cannot be modified easily. Therefore modification plans are restricted to the rearrangement of existing partitions, or purchasing new partitions of different dimensions.
Despite the above disadvantages however, welded metal partition frames remain the most commonly used type since the strength is high and manufacturing cost is low compared to conventional alternatives.
A significant recent development in partition design relates to the increasing demands being put on office furniture to accommodate various communication devices such as computers, telephones, facsimile machines, printers and the like.
In order to accommodate the increasing number of electrical and communication wires required in most modern office environments, wire or cable raceways through the hollow interior of partitions have been provided. The common conventional location for such a raceway is at the base or cap of a partition.
The individual conventional partitions each have a raceway or several raceways which communicate with each other when assembled in a modular partition wall. The raceway also commonly communicates with the electrical system of the occupied building through vertical power poles which extend up through the drop ceiling of the building office space or through monuments and access openings in the floor of the office space.
U.S. Pat. No. 4,133,153 to Hage describes a typical conventional partition raceway. The base portion of the Hage partition is essentially a hollow accessible beam within which electrical and communication wiring can be placed. The conventional partition frame is connected to the top of the hollow beam forming the cable raceway.
U.S. Pat. No. 5,038,539 to Kelly et al describes another example of a partition system which may accommodate cables at the base and at the cap of a conventional partition system. The vertical frame members are not modified in such a system but rather the cables are passed over the vertical frame members around their outward edges. This type of system may accommodate limited numbers of relatively thin cables retaining them within the space occupied by the cladding panels.
An alternative conventional method of passing wires between frames is described in U.S. Pat. No. 4,535,577 to Tenser et al. In this conventional system openings are made in the web section of vertical frame members. The electrical and communication wiring are threaded through the web openings. Therefore wires are not visible but are entirely concealed by the cladding panels. An advantage of this system is that the outward edges of vertical frame members remain completely clear. Accordingly the attachment of other components of modular office furniture systems is not impeded by cables overlapping the openings upon which shelves and other components are hung.
A distinct disadvantage of such a system is the need to thread cables through the openings. When installing, moving or maintaining computers or other office equipment, it may become frequently necessary to install and remove the cables. Increased labour costs and wear on the cables results from such a system. However since the web portion of the frame member contributes minimally to the strength of the frame member, providing such openings does not reduce the strength of the frame significantly.
Since most office equipment is operated on the top of a desk or table, current partition designs often include what is known as a "waist-line" waist height cable raceway. Electrical receptacles and various wires are accommodated at waist height thereby eliminating wires which hang down from table top to "base-line" receptacles located at the bottom of a partition. Use of a waist-line raceways simplifies installation and maintenance of equipment by eliminating the need for the installer to crawl under furniture to access a base-line cable raceway and electrical receptacles. The use of a waist height raceway also generally reduces the length of cables required between devices all located at a table top elevation.
An open interior partition system is sold under the trade mark OPTIMA by Design Finish Studio of Israel. This conventional partition is constructed of vertical sheet metal channel posts with pairs of horizontal round tubes. The pairs of horizontal tubes at each of their ends are inserted into specially designed molded plastic end connectors. The plastic connectors are snap-locked into the interior throat of the vertical channel posts to complete a rigid connection. The partition accommodates wires and cables within its interior by threading wires etc between the pairs of tubes and through openings punched in the webs of the vertical post channels.
This type of partition remains at a disadvantage since special molded connectors must be used, and the wires must be threaded between partitions through openings in the web of the posts.
Threading of wires through openings increases the time and effort required to install, remove and maintain office equipment, and increases wear on the outer insulated surfaces of the wiring, thereby reducing its service life.
However in such a conventional partition, since the entire internal space is open, between pairs of horizontal tubes, wires and cables may be accommodated at any level within an individual partition in the interior behind removable panels. Additionally, the panels are coupled to the horizontal beams with resilient tabs, rendering the entire internal cavity easily accessible through removable panels.
Therefore it is desirable to provide a partition which may easily accommodate electrical and communication cables preferably at any height in a manner which simplifies the installation, removal and maintenance of such equipment.
Also it is desirable to protect and conceal wiring and receptacles as much as possible behind cladding panels while maintaining the structural integrity of the partition frame.
The simplification of frame construction may result in significant cost savings in respect of the type of fabrication machinery used in manufacturing, savings in inventory costs, and enhancement of production scheduling.